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Nesterboy [21]
3 years ago
15

Please help thank you.

Mathematics
1 answer:
Mnenie [13.5K]3 years ago
7 0

Answer:

Option D

Step-by-step explanation:

Whenever we take a square root of a number the ± sign is with it like here in the question

x^2=20\\\\Apply\ square\ root\ on\ both\ sides\\sqrt{x^2}=\sqrt{20}  \\\\The\ square\ cancels\ out\ with\ the\ root\x=\sqrt{20}

And then x = ±4.47 which means x has two values one is +4.47 and the other is -4.47 so Option D is our answer.

You might be interested in
A refrigerator costs $580 a year to run. A family purchases a new one for $1200 that will save them 22% annually in energy costs
NeTakaya

Answer:

It will take nine years and four months for the refrigerator to pay for itself.

Step-by-step explanation:

The new refrigerator which costs $1200, saves the family 22% annually in energy cost.

Since the old refrigerator costs $580 to run, we want to determine how many years it will take for 22% of $580 per year to make $1200.

22% of $580

= 580 × 0.22

= 127.6

That is, it saved then $127.6 per year.

Now,

$1200/127.6

≈ 9.4

Which means, it will take 9 years and 4 months for the refrigerator to pay for itself.

7 0
3 years ago
Write an equation the describes the line passing through point (-2,8) with slope 4/5
andre [41]

Answer:

point-slope form: y-8=\frac{4}{5}(x+2)

Step-by-step explanation:

hope this helps :)

7 0
2 years ago
Help on this question
malfutka [58]

Step-by-step explanation:

always write what you know

circumference

U = 2 x pi x r

r = d/2

U = 39.25

rearrange and solve for r

U / (2 x pi) = r

solve for diameter

2r = d

6 0
3 years ago
Why is math important “?
Pavlova-9 [17]

Answer:

Without math, how would we know how to count seconds minutes, etc.?

Math is extremely important for knowing how to do simple things like cooking, you need to know for how much time to put something in the oven or microwave or stove. Those are just the basics. There is a lot more stuff out there that math is used for.

4 0
3 years ago
Read 2 more answers
Help asap
Nikolay [14]
First, you would create an equation for this problem. 
\frac{18}{15}= \frac{x}{100}

Next, you would cross multiply. 
15x = 1,800

Now, you would isolate the x. To do this, you would divide both sides by 15. 
x = 120

It is a 120% increase. 

I hope this helps!
7 0
3 years ago
Read 2 more answers
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